With developments of modern road transport system and advanced vehicle technology, active safety performance technology of the vehicle is paid more attention increasingly.
Many factors may affect the active safety performance, such as dimensions of the vehicle design, drive power, the suspension structure of the vehicle, the steering performance of the vehicle, etc. Especially, the steering performance of the vehicle directly determines the active safety performance of the vehicle.
The vehicle with the conventional two-wheel steering system has slow steering response and nonflexible steering at low speed, and has poor directional stability at high speed. In addition, the two-wheel steering system in the related art is mostly driven by two rear wheels, and steered by two front wheels. Thus, the steering scope of the vehicle has been greatly restricted, and it is needed a certain region to steer. Sometimes, because the region is too small, the vehicle cannot turn circle once, only can turn back and then turn circle.